1. Field of the Invention
The present general inventive concept generally relates to a battery pack, an electronic apparatus including the same, and a method of controlling charging, and more particularly, to a battery pack which is capable of preventing deformation of a battery due to over discharge, an electronic apparatus including the same, and a method of controlling charging.
2. Description of the Related Art
A portable electronic apparatus such as a notebook Personal Computer (PC), a convertible notebook PC, a tablet PC, a smart phone, and the like is equipped with a battery pack that is a power supply device. As a recent electronic apparatus provides mobility and a light weight short small design, an embedded lithium ion battery has been employed.
A lithium ion battery cell may be roughly divided into a cylinder-shaped battery cell, a square-shaped battery cell, and a polymer cell, and swelling may occur under an abnormal condition due to chemical characteristics of a battery. It is reported that the swelling occurs the most in a polymer cell whose cell case is made of a pouch material, not a metal material, and occurs often in a square-shaped cell as well. Such swelling usually occurs under such three abnormal conditions as over charge, over discharge, and exposure to a high temperature.
Herein, the swelling due to the over discharge may occur when a user does not use an electronic apparatus for a long time, but may occur when the user uses the electronic apparatus.
To be specific, when an abnormal condition of a battery cell is sensed and a protective circuit (specially, a fuse) operates, a current inflow to the battery cell is cut off by the operation of the fuse. In this case, the user should visit an after-sales service center and replace the battery pack. However, the electronic apparatus may operate when it is connected to a charger, and thus, there are some users to continuously use the electronic apparatus without replacing the battery pack.
However, when the electronic apparatus is used for a long time in such a state, the battery cell where the current inflow is cut off may be over discharged due to a natural discharge, which may result in the swelling. Particularly, in a case of an embedded lithium ion battery pack, the other components within the electronic apparatus may be damaged due to the swelling of the battery pack.